A ‘typical’ SSW event involves a ridge of high pressure and warm air blossoming over the Bering Sea and then flooding into the Arctic Circle. The primary oscillation that involves the stratosphere is the Quasi-Biennial Oscillation (QBO), and that is where we will begin this section. In the winter, there is a large vortex spanning the entirety of the atmosphere relevant to weather forecasting, from the surface to the upper reaches of the stratosphere. The presence of strong positive SST anomalies in the Bering Sea indicate a materially-increased chance of sudden stratospheric warmings this winter, which therefore increase the risk of severe outbreaks of cold air into the United States. This holds special importance in my opinion given how critical the Bering Sea is for the stratosphere during the winter, thus making it a critical factor in the North American winter pattern as well. In addition to the three primary oscillations discussed above, there are five areas I monitor that I believe also affect the winter pattern to a non-trivial degree. Undoubtedly, if you have any interest in the broad weather pattern during the winter months, you’ve heard of the infamous “polar vortex” at some point or another.

As mentioned at the start of this section, Figure 28 would be used for the first three areas of interest. This is most pertinent for lake-effect snow purposes, but may also dictate temperature trends to some degree for areas immediately downwind of the Lakes. Referring back to Figure 29, the crude temperature anomalies shown for the Great Lakes show essentially all of the Lakes as being above-normal in sea surface temperatures, an indication that enhanced lake-effect snowfall is possible for areas downwind this winter. Let’s take a look back at Figure 28 and focus our attention on the Bering Sea. I came back because my “like” didn’t take. Those who take care of farm animals often grow fond of them. The majority of concerns around the Gulf of Alaska were taken care of in the Pacific Decadal Oscillation section, so this section should be brief. It is necessary to view sea surface temperature anomalies in the Gulf of Alaska in their own right, outside of the PDO, however, warranting a separate section here. However, I have already predicted in the Sun Newspaper that the new Independent party will form when the Labour Party splits. This paper focuses on the question of what needs to be predicted and what processes need to be understood to predict and forecast space weather conditions that are hazardous to current technology.

Now that I’ve gotten that off my chest, we need to turn to the question of ‘what causes these splits in the polar vortex?’. We’ll use the answer to the second question to also answer the first question. The graphic itself shows mean zonal winds, in meters per second. The x-axis shows latitudes from the Equator to the Arctic Circle, while the y-axis shows the atmosphere by height, in millibars. Zonal winds are winds that run west-to-east: when the graphic shows positive zonal wind values, it means winds are going west-to-east, while negative zonal wind values indicate winds are running east-to-west. One can confirm this by viewing the large positive swath of zonal winds at the 200-millibar level, positioned around the 40 degree North line of latitude. Figure 28 shows a swath of well-above-normal SST anomalies in the Gulf of Alaska and northeast Pacific as a whole, an interesting development should it persist into the winter.

While there are pockets of below-normal SSTAs in the waters surrounding southern Japan, as well as due east of the country, there is also a swath of above-normal anomalies just northeast of Japan, with essentially-neutral anomalies in between. In general, above-normal water temperatures encourage the development of high pressure systems, while below-normal water temperatures encourage the development of low pressure systems. Even if this doesn’t materialize, and we keep our attention only on the Gulf of Alaska, the strong positive SSTAs are supportive of a high pressure system over that area. As discussed in the prior section for the Gulf of Alaska, warmer than normal SSTs tend to be associated with high pressure systems. Temperatures may also average warmer than normal for those areas, especially if the positive anomalies increase. In extreme cases, the magnetic storms may have significant effects on the power grids used by millions of households. This may change as we review more material – this is only one section of this outlook, of course! A potential exception is Lake Superior, where anomalies are zero to even slightly negative, but anomalies across all of these lakes could change substantially by the time winter actually rolls around. According to the National Weather Service (NWS), the Upper Mississippi Valley, the Upper Great Lakes and the Sierra Nevadas will all be hit by heavy snow through Monday night.